Estimating a Large Drive Time Matrix between Zip Codes in the United States: A Differential Sampling Approach

Estimating a massive drive time matrix between locations is a practical but challenging task. The challenges include availability of reliable road network (including traffic) data, programming expertise, and access to high-performance computing resources. This research proposes a method for estimating a nationwide drive time matrix between ZIP code areas in the U.S.--a geographic unit at which many national datasets such as health information are compiled and distributed. The method (1) does not rely on intensive efforts in data preparation or access to advanced computing resources, (2) uses algorithms of varying complexity and computational time to estimate drive times of different trip lengths, and (3) accounts for both interzonal and intrazonal drive times. The core design samples ZIP code pairs with various intensities according to trip lengths and derives the drive times via Google Maps API, and the Google times are then used to adjust and improve some primitive estimates of drive times with low computational costs. The result provides a valuable resource for researchers

Security feature measurement for frequent dynamic execution paths in software system

© 2018 Qian Wang et al. The scale and complexity of software systems are constantly increasing, imposing new challenges for software fault location and daily maintenance. In this paper, the Security Feature measurement algorithm of Frequent dynamic execution Paths in Software, SFFPS, is proposed to provide a basis for improving the security and reliability of software. First, the dynamic execution of a complex software system is mapped onto a complex network model and sequence model. This, combined with the invocation and dependency relationships between function nodes, fault cumulative effect, and spread effect, can be analyzed. The function node security features of the software complex network are defined and measured according to the degree distribution and global step attenuation factor. Finally, frequent software execution paths are mined and weighted, and security metrics of the frequent paths are obtained and sorted. The experimental results show that SFFPS has good time performance and scalability, and the security features of the important paths in the software can be effectively measured. This study provides a guide for the research of defect propagation, software reliability, and software integration testing

Characterization of a multidrug-resistant porcine Klebsiella pneumoniae sequence type 11 strain coharboring blaKPC-2 and fosA3 on two novel hybrid plasmids

The occurrence of carbapenemase-producing Enterobacteriaceae (CPE) poses a considerable risk for public health. The gene for Klebsiella pneumoniae carbapenemase-2 (KPC-2) has been reported in many countries worldwide, and KPC-2-producing strains are mainly of human origin. In this study, we identified two novel hybrid plasmids that carry either blaKPC-2 or the fosfomycin resistance gene fosA3 in the multiresistant K. pneumoniae isolate K15 of swine origin in China. The blaKPC-2-bearing plasmid pK15-KPC was a fusion derivative of an IncF33:A−:B− incompatibility group (Inc) plasmid and chromosomal sequences of K. pneumoniae (CSKP). A 5-bp direct target sequence duplication (GACTA) was identified at the boundaries of the CSKP, suggesting that the integration might have been due to a transposition event. The blaKPC-2 gene on pK15-KPC was in a derivative of ΔTn6296-1. The multireplicon fosA3-carrying IncN-IncR plasmid pK15-FOS also showed a mosaic structure, possibly originating from a recombination between an epidemic fosA3-carrying pHN7A8-like plasmid and a pKPC-LK30-like IncR plasmid. Stability tests demonstrated that both novel hybrid plasmids were stably maintained in the original host without antibiotic selection but were lost from the transformants after approximately 200 generations. This is apparently the first description of a porcine sequence type 11 (ST11) K. pneumoniae isolate coproducing KPC-2 and FosA3 via pK15-KPC and pK15-FOS, respectively. The multidrug resistance (MDR) phenotype of this high-risk K. pneumoniae isolate may contribute to its spread and its persistence

ZnS/CuS nanoparticles encapsulated in multichannel carbon fibers as high-performance anode materials for flexible Li-ion capacitors

Transition metal sulfides (TMSs) are widely recognized for their potential as anode materials in the development of flexible lithium-ion capacitors (FLICs) owing to their high theoretical capacity. However, their practical application has been significantly limited by rapid capacity decay and sluggish kinetics associated with TMS volume variation. In response to these challenges, we have prepared ZnS/CuS nanoparticles embedded in continuous and multichannel carbon fibers (CFs). This was achieved through a process involving blow-spinning and subsequent sulfidation. Notably, the electrochemical performance of these materials was largely improved, owing to the synergistic effect of bimetallic sulfides. The ZnS/CuS-CF anode material demonstrated a high specific capacity of over 900 mAh g−1 at a current density of 0.2 A g−1. Furthermore, it exhibited superior rate capacity (300 mAh g−1 at 20 A g−1) and excellent cyclic stability, maintaining its performance over 1000 cycles at 10 A g−1. We also prepared lithium-ion capacitors (LICs) using the same method. These LICs exhibited a maximum energy density of 136 Wh kg−1, a high power density of 43.5 kW kg−1, and an impressive cyclic stability over 4000 cycles. In addition, the FLICs, when configured in the form of a pouch cell, demonstrated significant potential for the development of smart, flexible electronic devices

Atomic Sn–enabled high-utilization, large-capacity, and long-life Na anode

Constructing robust nucleation sites with an ultrafine size in a confined environment is essential toward simultaneously achieving superior utilization, high capacity, and long-term durability in Na metal-based energy storage, yet remains largely unexplored. Here, we report a previously unexplored design of spatially confined atomic Sn in hollow carbon spheres for homogeneous nucleation and dendrite-free growth. The designed architecture maximizes Sn utilization, prevents agglomeration, mitigates volume variation, and allows complete alloying-dealloying with high-affinity Sn as persistent nucleation sites, contrary to conventional spatially exposed large-size ones without dealloying. Thus, conformal deposition is achieved, rendering an exceptional capacity of 16 mAh cm−2 in half-cells and long cycling over 7000 hours in symmetric cells. Moreover, the well-known paradox is surmounted, delivering record-high Na utilization (e.g., 85%) and large capacity (e.g., 8 mAh cm−2) while maintaining extraordinary durability over 5000 hours, representing an important breakthrough for stabilizing Na anode

Endoscopic Surgery for Supratentorial Deep Cavernous Malformation Adjacent to Cortical Spinal Tract: Preliminary Experience and Technical Note

In this study, we aimed to introduce a technical note and to explore the efficacy of endoscopic surgery combined with diffusion tensor imaging (DTI) navigation for supratentorial deep cerebral cavernous malformations (CCM). A prospectively maintained database of CCM patients was reviewed to identify all CCM patients treated by endoscopic surgery. The sagittal T1-weighted anatomical magnetic resonance imaging (MRI) and DTI were acquired before surgery. Endoscopic surgery was planned and performed based on preoperative DTI images and intraoperative DTI navigation. All patients were followed up more than 6 months. Motor function deficit and modified Rankin scale (mRS) scores were documented on follow-up. A final mRS score of 0–2 was considered a good outcome, and a final mRS score >2 was considered a poor outcome. Second DTI and 3DT1 were performed at 3 months after surgery. We tracked the ipsilateral corticospinal tract (CST) on pre- and postoperative DTI images. The overall mean FA values and the number of fibers of tracked CST were compared on pre- and postoperative DTI images. Risk factors associated with motor deficits and poor outcomes were analyzed. Seven patients with deep CCM and treated by endoscopic surgery were enrolled in this study. The mean value of preoperative mRS was 1.5 ± 0.98, but that score recovered to 0.86 ± 1.22 3 months later. The mRS scores were improved significantly according to statistical analysis (p = 0.012). According to the Spearman non-parametric test, only the fiber number of ipsilateral CST on postoperative DTI was significantly associated with muscle strength 6 months after surgery (p = 0.032). Compared with preoperative CST characteristics on DTI, the change of FA value (p = 0.289) and fiber number (p = 0.289) of ipsilateral CST on postoperative DTI was not significant It meant that the CST was protected during endoscopic surgery. Endoscopic surgery based on DTI navigation might be an effective method to protect fiber tracts in supratentorial deep CCM patients and improve long-term outcomes. However, more studies and cases are needed to confirm our findings

Single domain antibody multimers confer protection against rabies infection

Post-exposure prophylactic (PEP) neutralizing antibodies against Rabies are the most effective way to prevent infection-related fatality. The outer envelope glycoprotein of the Rabies virus (RABV) is the most significant surface antigen for generating virus-neutralizing antibodies. The small size and uncompromised functional specificity of single domain antibodies (sdAbs) can be exploited in the fields of experimental therapeutic applications for infectious diseases through formatting flexibilities to increase their avidity towards target antigens. In this study, we used phage display technique to select and identify sdAbs that were specific for the RABV glycoprotein from a naïve llama-derived antibody library. To increase their neutralizing potencies, the sdAbs were fused with a coiled-coil peptide derived from the human cartilage oligomeric matrix protein (COMP48) to form homogenous pentavalent multimers, known as combodies. Compared to monovalent sdAbs, the combodies, namely 26424 and 26434, exhibited high avidity and were able to neutralize 85-fold higher input of RABV (CVS-11 strain) pseudotypes in vitro, as a result of multimerization, while retaining their specificities for target antigen. 26424 and 26434 were capable of neutralizing CVS-11 pseudotypes in vitro by 90–95% as compared to human rabies immunoglobulin (HRIG), currently used for PEP in Rabies. The multimeric sdAbs were also demonstrated to be partially protective for mice that were infected with lethal doses of rabies virus in vivo. The results demonstrate that the combodies could be valuable tools in understanding viral mechanisms, diagnosis and possible anti-viral candidate for RABV infection

GIS Automated Delineation and Analysis of Cancer Service Areas in the United States

Delineating a meaningful and reliable geographic unit pertaining to cancer care is essential in examining geographic variations in cancer care for better analysis, management, and planning. Public health researchers have devoted great efforts to defining various service areas, which; however, lack scientific rigor or are unrepresentative of the highly specialized cancer care markets, and their methods have become obsolete in the era of big data and high geo-computation. This study develops the “Spatially Constrained Leiden (ScLeiden)” method, a network community detection algorithm in Geographic Information Systems (GIS), and applies it to delineate a series of coherent cancer service areas (CSAs) in the U.S. Using the national Medicare enrollment and claims, this study creates a spatial network of cancer cares across the U.S. where each network edge represents the service volume of cancer-directed surgery, chemotherapy, and radiation between ZIP codes. It then develops and automates the ScLeiden method in an easy-to-use GIS toolkit. The method explicitly maximizes the service volumes within defined areas and accounts for spatial contiguity and other constraints. Its derived service areas outperform existing areas in terms of self-containment and size comparability. The method is applied to define multiscale CSAs in comparable numbers to census regions, divisions, and states. The results provide valuable guides for stakeholders to more effectively coordinate cancer care and advance efforts in cancer control and prevention across and within states. The National Cancer Institute mandates its designated cancer centers to identify catchment areas for assessing cancer burden and needs. To assist this effort, this study refines the ScLeiden method to delineate nationwide CSAs anchored by major cancer centers, identified by the Association of American Cancer Institutes. The result can be used as reliable units to evaluate cancer care in areas within versus outside the catchment areas of these designated cancer centers, and inform more evidence-based policy. The work will have a major impact on the research and stakeholder communities engaged in evaluating geographic variations in health care delivery and outcomes. The toolkit and CSAs will be widely disseminated, thus empower them to define any units pertaining to their specific health care systems and needs

Network optimization approach to delineating health care service areas: Spatially constrained Louvain and Leiden algorithms

Constructing service areas is an important task for evaluating geographic variation of health care markets. This study uses cancer care as an example to illustrate the methodology, with the nine-state Northeast Region of the U.S. as the study area. Two recent algorithms of network community detection are implemented to account for additional constraints such as spatial connectivity and threshold region size. The refined methods are termed “spatially-constrained Louvain (ScLouvain)” and “spatially-constrained Leiden (ScLeiden)” algorithms, corresponding to their predecessors Louvain and Leiden algorithms, respectively. Both are network optimization methods that maximize flows within delineated communities while minimizing inter-community flows. The service areas derived by the methods, termed “Cancer Service Areas (CSAs)”, are more favorable than the commonly used comparable unit, Hospital Referral Regions (HRRs) for evaluating cancer-specific variation in care. Between the two, the ScLeiden performs better than ScLouvain in modularity, localization index and computational efficiency, and thus is recommended as an effective and efficient approach for defining functional regions

Assessing the Role of Policies on Land-Use/Cover Change from 1965 to 2015 in the Mu Us Sandy Land, Northern China

Policy has long been considered one of the major driving forces for land-use/cover change. However, research on the interactions between land-use/cover change (LUCC) and relevant policies remains limited. The agropastoral ecotone is a typical area of policy implementation and LUCC. Therefore, this study integrates the use of multisource and multiresolution remote sensing and topographic and field-based datasets for the case of the Mu Us Sandy Land (MUSL) in northern China. The research aim was to quantify LUCC from 1965 to 2015 and describe the relationship between policy changes and land-use types during three stages: the stage of the Great Cultural Revolution, the stage of the modernization of the economy, and the stage of the Great Ecological Project. The results indicated that land use was affected by different national policies because of the national approach to land use during different periods. In the stage of the Great Cultural Revolution, the amount of cultivated land increased, and the environment deteriorated under the influence of leftists. In the stage of the modernization of the economy, vegetation coverage improved after the initial damage, and cultivated and artificial surfaces also increased. In the stage of the Great Ecological Project, cultivated land and unused land decreased, and woodland and sparse vegetation increased with the implementation of the Grain for Green Project (GGP). However, cultivated land increased but wood land and sparse vegetation decreased significantly by the end of the GGP. The coverage of artificial surfaces increased and grasslands decreased due to the encroachment of artificial surfaces into grasslands